Nutrition Graduate Program, Health Sciences Center, Federal University of Santa Catarina, Av. Prof. Henrique da Silva Fontes, 321, Trindade, Florianópolis, SC, 88040-370, Brazil; Department of Physiological Sciences, Federal University of Santa Catarina, R. Eng. Agronômico Andrei Cristian Ferreira, 239, Carvoeira, Florianópolis, SC, 88040-900, Brazil.
Neuroscience Graduate Program, Biological Sciences Centre, Federal University of Santa Catarina, Campus Universitário, Campus Universitário, s/n, Sala 208, Bloco E, Prédio Administrativo - Córrego Grande, Trindade, Florianópolis, SC, 88040-900, Brazil; Department of Physiological Sciences, Federal University of Santa Catarina, R. Eng. Agronômico Andrei Cristian Ferreira, 239, Carvoeira, Florianópolis, SC, 88040-900, Brazil.
Clin Nutr ESPEN. 2021 Feb;41:225-233. doi: 10.1016/j.clnesp.2020.12.009. Epub 2021 Jan 4.
Relative fat mass (RFM) is a new method to estimate whole-body fat percentage in adults using an anthropometric linear equation. We aimed to assess the association between RFM and body fat (BF), evaluated by dual x-ray absorptiometry (DXA) or bioelectrical impedance (BIA), in young male adults.
Eighty-one young males were assessed for BF fat and free fat mass (by BIA and DXA), waist circumference. BMI and RFM were then calculated from data collected from the subjects. The agreement between BMI and RFM or BIA/DXA was assessed by Pearson's Correlation and Kappa index. Univariate and multivariate linear regression were applied.
Analyzing all the participants together, the correlation between RFM and DXA (r = 0.90) or RFM and BIA (r = 0.88) were slightly higher than the correlation between BMI and DXA (r = 0.79) or BMI and BIA (r: 0.82). When analyzed by BF, low BF (LBF) individuals showed a much higher correlation with RFM (r = 0.58; r = 0.73) than BMI (r = 0.24; r: 0.46). However, subjects with excess BF (EBF) presented similar correlations when comparing RFM (r = 0.80; r = 0.64) and BMI (r = 0.78; r = 0.64). In general, RFM presented a higher strength of agreement with DXA and BIA (k = 0.75; k = 0.67) than BMI (k = 0.63; k = 0.60). Multivariable linear regression also revealed high associations between RFM and DXA or RFM and BIA (r = 0.85; r = 0.81).
Our findings suggest that RFM shows a good correlation and association with BF measured by DXA and BIA in young male adults. Furthermore, RFM seems to be better correlated to BF in LBF individuals when compared to BMI. Therefore, further studies investigating RFM as a tool to assess BF and obesity are motivated.
相对脂肪量（RFM）是一种使用人体线性方程来估计成年人全身脂肪百分比的新方法。我们旨在评估 RFM 与体脂肪（BF）的相关性，BF 通过双能 X 射线吸收测定法（DXA）或生物电阻抗（BIA）评估，在年轻男性中。
对 81 名年轻男性进行 BF 脂肪和游离脂肪质量（通过 BIA 和 DXA）、腰围、BMI 和 RFM 的评估。然后从受试者的数据中计算 BMI 和 RFM。通过 Pearson 相关系数和 Kappa 指数评估 BMI 和 RFM 或 BIA/DXA 之间的一致性。应用单变量和多变量线性回归。
分析所有参与者，RFM 与 DXA（r=0.90）或 RFM 与 BIA（r=0.88）的相关性略高于 BMI 与 DXA（r=0.79）或 BMI 与 BIA（r：0.82）的相关性。当按 BF 分析时，低 BF（LBF）个体与 RFM（r=0.58；r=0.73）的相关性明显高于 BMI（r=0.24；r：0.46）。然而，比较 RFM（r=0.80；r=0.64）和 BMI（r=0.78；r=0.64）时，有多余 BF（EBF）的受试者具有相似的相关性。一般来说，RFM 与 DXA 和 BIA（k=0.75；k=0.67）的一致性高于 BMI（k=0.63；k=0.60）。多变量线性回归也揭示了 RFM 与 DXA 或 RFM 与 BIA 之间的高度相关性（r=0.85；r=0.81）。
我们的研究结果表明，RFM 与年轻男性中 DXA 和 BIA 测量的 BF 之间具有良好的相关性和关联性。此外，与 BMI 相比，RFM 在 LBF 个体中与 BF 的相关性似乎更好。因此，有动机进一步研究 RFM 作为评估 BF 和肥胖的工具。
